It's kept me sane during college. So many times I've thought I was going to drop out, but I've put up with all the BS and I'm a year from graduating. Pretty sure if I didn't smoke I would of lost my cool a long time ago, dropped out, and be working a job that I hate.
I also have had pretty bad anxiety the past 6-7 years of my life, and it helps my mind slow down, quit worrying, and be able to relax.
It's not for everyone, but it's part of my daily regimen for a healthy mind and spirit. To each their own.